Difficulty Soldering

Soldering to conductive ink is not the same as soldering to copper traces. Ensure you review our best practices before printing to avoid wasting ink.

Common Problems

Read this section to address the most common soldering problems.

Was the circuit baked long enough?

Symptoms of poor baking include browning of the pads. Make sure you allowed enough time for the bake to finish and cool down. If not, you need to restart your circuit.

Was the circuit flipped during the bake process?

The circuit must have been flipped after printing and placed on the clamp ledges, ink facing towards the print platform, for the conductive ink to bake properly

Was the circuit burnished?

Burnished pads should appear faintly silver, not white. If the pads still appear white it may be possible to salvage the pad by burnishing until it appears silver. This does not usually work after soldering has been attempted.

Are you using the correct solder alloy, flux and temperature?

Most solder alloys will damage Voltera PCBs. Use the supplied solder alloy, flux and correct temperature.

Is the ink expired?

With proper storage, the ink has an expected shelf life of 6 months. Inspect the label on your ink cartridge and check when it was packaged. Expired ink may present difficulties when soldering.

Hand Soldering Problems

Refer to the tutorial for proper procedures to hand solder Voltera PCBs.

Solder does not wet the pad

The provided solder wire does not have flux. Always apply generous amounts of flux separately.

The pad can damaged by excessive heat or soldering time. In these cases, the ink will appear dark brown or black, and solder will ‘ball up’ on the ink. Circuit damage is irreversible, so if this happens you must re-print the circuit. Temperature control is critical to good soldering!

Components break off

While the Voltera ink is quite hard after baking, it is also brittle. Applying too much shear stress or torsion will break the ink. Take care when handling soldered components.

For components that will be put under stress, choose through-hole components. This includes connectors, headers, and components such as trimpots or variable resistors that will be adjusted manually.

Reflow does not melt solder paste

The built-in Voltera reflow profile should be sufficient for the majority of cases.

If you are reflowing boards thicker than 1.6 mm or if you have very large components, use the Manual Reflow feature to ensure the board reaches the required temperature.

Do not leave solder paste on the board for extended periods. Reflow the board immediately after dispensing or applying solder paste for best results.

Solder Paste is Balling Up

If you are trying to reflow solder paste on a bare pad with no component, solder paste will ball up. However, balling up on a bare pad is not an indication of poor soldering quality!

Unlike copper, the conductive ink surface is not completely metal, which means that solder needs some encouragement to form a cohesive layer - this is accomplished by placing a component on the paste.

To get a good solder joint and good wetting, you need to have a component on the pad for the paste to 'anchor' to. Because the melted paste is distributed evenly both over the component lead and the conductive ink surface, it will form good quality solder joints with the silver in the ink.